Tire removing apparatus with circumferentially distributed thrust members



E. DOUGLASS 2,647,564 TIRE REMOVING APPARATUS WITH CIRCUMFERENTIALLYDISTRIBUTED THRUST- MEMBERS Filed March 4, 1947 3 Sheets-Sheet 1 Aug. 4,1953 IN V EN TOR. fi m/57- 0006-4 455 Aug. 4, 1953 E. DOUGLASS 2,647,564

TIRE REMOVING APPARATUS WITH CIRCUMFERENTIALLY DISTRIBUTED THRUSTMEMBERS 5 Sheets-Sheet 2 Filed March 4, 1947 INVENTOR.

by Z v Z2 Aug. 4, 1953 Filed March 4, 1947 E. DOUGLASS TIRE REMOVINGAPPARATUS WITH CIRCUMFEREMTT AL LY DISTRIBUTED THRUST MEMBERS QWN.

- INVENTOR.

5211/55 7' 004/64 Ass flrroewax Patented Aug. 4, 1953 OFFICE TIREREMOVING APPARATUS WITH CIRCUMFERENTIALLY DISTRIBUTED THRUST MEMBERSErnest Douglass, Pomona, Oalif., assignor to Homer L. Hunsicker, BeverlyHills, Calif.

Application March 4, 1947, Serial No. 732,355

1 Claim. 1

My invention relates to the field of tire removing mechanisms and moreparticularly to a hydraulically operated tire removing device adaptedfor use with tires of industrial sizes.

In providing a mechanism for demounting a pneumatic tire, considerationmust be given to the difference existing between the rim used forsupporting an industrial tire in contrast to that used on relatively thesame size tire in the passenger car tire field. Although in the earlydevelopment of the pneumatic tire, all tires due to the relativelyinflexible character of their carcasses were supported on rims whichallowed them to be slidably mounted or demounted therefrom, such is nolonger the situation,

On this early type of rim the pneumatic tire was held between a fixedflange and a removable ring which ring due to its resiliency was adaptedto remain in place on the rim after having been expanded and forcedthereon. With the advent of the low pressure balloon type tire, with itslighter and more flexible type of carcass construction, it was found inthe passenger car size that such a tire could be temporarily deformedand forced on a rim having the flanges made integral therewith.

However, this condition does not prevail in the industrial field inwhich both the balloon and high pressure type tire are still mounted onthe early type rim that is provided with a removable ring. Thisdifference in mounting between the passenger and industrial type tiremay be easily accounted for when it is considered that in the industrialfield a tire must be constructed with a large number of plies towithstand the great loads and shocks to which it will be subjected.Thus, the resulting heavy duty industrial type balloon tire althoughoperated at low pressure is formed with such an inflexible carcass thatthe beads on same cannot be sprung over the flanges of a rim as is donein a passenger car tire, but must be slidably mounted or demounted froma rim provided with a removable ring.

As my invention operates by slidably removing the tire from the rim itwill be apparent that while it has but little application in thepassenger car field, it will find wide application in the industrialfield for both high pressure and balloon type heavy duty pneumatictires. In the industrial field my invention will be found particularlyuseful in the removal of heavy duty tires from such mechanical equipmentas trucks, busses, tractors, earth moving machinery, airplanes, and morerecently amphibious vehicles as perfected by the armed i6$ such as theDu-ck."

A difliculty encountered in using heavy duty pneumatic tires is theremoval of the tire from the rim after long usage. This difiiculty ofremoving the tire may be considered as arising from the combined effectof several factors. The first of these factors is the heat generated bythe flexing of the plies as the tire is rapidly rotated, and thetendency of the tire to heat up,due to the inability of the heatgenerated in the interior plies to escape therefrom. The second factorinvolves the weather conditions to which the tire is subjected, andwhich includes the passage of the tire through mineral carrying water invarious forms such as puddles, flooded areas, slush and the like. Asmall amount of this water seeps inwardly between the outer face of thebead and the inner face of the rim, and due to the heating action of thetire as it rotates is expelled by evaporation, leaving the mineralcontent. After a prolonged period of time a mineral deposit is built upbetween the rim and bead of the tire that acts as a cement in bondingthem together, and may require a great force running into tons ofpressure to break. It will be readily apparent that unless considerablecare is used in removing a tire that is so bonded to its supporting rim,injury to the carcass of the tire will result.

The major object of my invention is to provide a stationary tiredemounting mechanism that is adapted for removing heavy duty industrialpneumatic tires from their rims with a minimum of expense, time, andmanual effort.

Another object of my invention is to furnish a device that while quicklyand efficiently removing a tire from its supporting rim will protect thecarcass thereof from the injury that happens so frequently when rubberhammers are employed for thi purpose.

These and other objects and advantages of my invention will appear fromthe following description of a preferred form therof, and from theaccompanying drawings wherein:

Figure 1 is a side elevation of my pneumatic tire demounting mechanism;

Figure 2 is a front elevational view of the same device taken on theline 22 in Figure 1;

Figure 3 is an enlarged longitudinal cross sectional View of thehydraulically operated portion of my tire demounting mechanism taken onthe line 33 in Figure 2;

Figure 4 is an enlarged cross sectional view of the pressure fingersupport taken on the line i4 in Figure 2; and

Figure 5 is-an alternate form of the centering cone used in securingcorrect alignment of the pneumatic tire supporting wheel prior todemounting the tire therefrom.

Referring now to the drawings, and particularly to Figures 1, 2 and 3thereof for the general arrangement of my invention it will be seen thatmounted in a vertical position is a hexagonally shaped spider S, withsix radially movable outwardly extending pressure fingers F supportedtherefrom, and which may be concurrently adjusted to a position adaptedfor removing a pneumatic tire T from a rim R, when the rim supportingwheel W is moved inwardly by a hydraulic cylinder C.

For supporting my invention I provide a base frame or floor sill it inthe form of'a symmetrical cross that includes cross arms H and 12respectively. It will be apparent that as the arms II and i2 are in thesame horizontal plane, the arm l I may be continuous with the arm [2being formed from two pieces of metallic material that are welded orotherwise secured to the arm H at the point of intersection. Althoughany heavy rigid material may be used for the base frame 18, I have foundit convenient to use commercially available I-beams of the desired crosssection for both the arms H and I2. Extending forwardly over the crossarm l2 a few inches, and rearwardly along the cross arm II a substantialdistance, is a rectangular base plate I3 that is preferably fabricatedfrom steel plate of from one-half to three-quarter inche in thickness.To secure the base plate 13 to the frame a number of machine bolts itare provided, and engage suitably disposed openings located in both thebase plate and the upper flanges of the arms H and I2. The purpose ofthe base I3 is to support the equipment used in actuating the hydrauliccylinder C, and which will hereinafter be discussed in detail.

To support the spider S in a vertical position a pair of supporting legsl are provided, with each leg being preferably formed from heavy steelbars of rectangular cross section, and extending downwardly andoutwardly from the lower exterior surface of the spider to the cross arm12. As the spider S when once placed in position need not again bemoved, I have found it desirable to Weld or otherwise permanently affixthe legs 25 to both the spider S and cross arm l2.

The spider S is fabricated as a unit by weldin six relatively heavysteel bars of equal length that constitute the side members I6, into thedesired hexagon shaped figure. Disposed at the center of the spider S isa horizontally positioned cylindrical spider hub 58, that is firmly heldin position by six outwardly extending diagonal members I? ofrectangular bar steel. The inwardly extending end of each diagonalmember I1 is affixed by welding to the exterior surface of the spiderhub l8 and the outwardly extending end to the interior face of thespider S at the junction point of each of the side members IS.

The width of the side members it and the length the cam plate 20, ajournal box 2! 0f cementional design is situated near the outer end ofone of the horizontal diagonal members I7, and is welded or otherwisepermanently affixed to the spider S. Rotatably supported in the journalbox 2! is a substantially horizontal shaft 22 that is provided on itsinwardly extending-portion with threads 23. A crank 24 affixed to theoutwardly extending end of the shaft 22, and provided with a suitablehandle 25, permits the shaft 22 to be manually rotated. For translatingthe rotational movement of the crank 24 into lateral motion suitable forrotating the cam plate 20, a cylindrical internally threaded member 26is furnished which engages the threaded portion 23 of the shaft.Pivotally joined to the cam plate 20 by a machine bolt 21 that engages asuitable opening provided therein, and on the opposite end by a pin 28to the inwardly disposed end of the internally threaded member 26, is aconnecting link 29 of conventional design. Thus as the shaft 22 isrotated by the crank 24, the member 26 and the connecting link 29 aremoved laterally and the cam plate 20 rotated, the importance of whichwill become apparent from a further reading of the specification.

Supporting each of the pressure fingers F used in slidably removing thetire T from the rim R. is a forwardly extending, substantiallyhorizontal, pressure arm 30 of rectangular cross section which isslidably mounted on one of the diagonal members ll by means of aU-shaped member 3|. Each of the U-shaped members 3!, as best seen inFigures 3 and 4, includes a pair of laterally spaced rectangular arms 32that embrace one of the diagonal members I1 and extend rearwardly ashort distance therebeyond. Engaging openings provided in thisrearwardly extending portion of the arms 32, and similar openingsprovided in a rectangular spacer bar 33 of rigid material insertedtherebetween, are a number of machine bolts 34. Thus, by tightening themachine bolts 34 and using a spacing bar 33 of the proper thickness, thedesired degree of frictional resistance may be secured between thediagonal member ll and the U-shaped member 3!. In addition, by removingthe machine bolts 34 and the spacing bar 33, the pressure arm 30 may beremoved and replaced by another arm should the occasion so require.

To permit concurrent radial movement of the pressure arms 30 as a group,due to rotating the shaft 22 with the crank 24, a lug 35 that extendsinwardly toward the hub I8 is situated on each of the U-shaped members3i, and with its forwardly disposed face in vertical alignment with theforward face of the cam plate 28. An inwardly extending link 38 ismovably supported and held on the forward face of each lug 35 by a pin31 that engages suitable openings provided in both members. The innerportion of each link 36 is movably joined to the cam plate 2% by amachine bolt 38 that may be placed in either of two openings 39 or 40,that are provided for each link on the cam 26. It will be noted inFigure 2 that the openings 39 and 40 are equally spaced on concentricbolt circles, with the bolt circle for the openings 40 being larger thanthat used for the openings 39. When the machine bolts 38 are changedfrom the openings 39 to the openings 40 a greater throw of each of thelinks 36 is obtained, and with a consequent more rapid and furtheroutward movement of the pressure arms 30. For convenience in changingthe machine bolts 38 from one of the openings 39 or 40 to the other, Ihave found it desirable to have the openaccuses ings so arranged ontheir-respective bolt circles that they are grouped together in pairs asmay best be seen in Figure 2. Although the machine bolts '38 arenormally situated in the cam plate openings 3-9, in the case ofexceptionally large tires where the maxi-mum radial movement of thefingers F is required the openings til are employed.

Each of the pressure fingers 3? used in slidably removing the tire 'Ifrom the rim includes a trapezoid shaped plate at having a rearwardlyand outwardly extending arm a la. A pair of the plates ll are disposedon opposite sides of the forwardly extending portion oi the pressure arm31} and are pivotaliy supported thereon by a hinge pin 42 that engages asuitable opening provided each arm l t a and in an extension (not shown)oi the pressure arm 80. Extending inwardly toward one another, andaffiued to the f rward end of each pair of plates li is a tapered orwedge shaped steel pressure plate is or" from one-eighth to one-quarterinch in thickness. it will be noted in Figure 2 that the widest portionof each of the pressure plates i3 is the inwardly disposed edge 63c,which is preferably ground or formed somewhat concave in order that itwill approximately fit the exterior surface of the various siged'rirnsthat will be encountered. As my inveption will be used for removingtires of various sizes, the curvature of the edge etc must necessarilybe such that it will fit all sizes of rims for which device adapted,rather than an exact fit for one particular size. Since the tire '1 isfirst contacted the forwardly extending edge 43a of each pressure plateis, and which is situst el considerab y inward f om the hinge pin '32, te p essure finger F w l pi ot nw d y as pressure is a plie to the tire util furthe m v scen is preve te by th case its contactin the exteriorsurface or" the r m For h lding the p essur fi gers F in su sta tie ly aho izontal pos tion p ior t the pressure plates t3 n agin the side Walof th t e T, a leaf spring to is provided for each pressure arm it andextends longitudi ly along the inner side thereof with its iorwardportion extending under and suppo tin the pa of trap i shaped plates ll.Due to the resiliency of the sprin :1 he pressur fin s returned to a poition substantially in alignment with the pressu e am it u o th pressurep at t ho e rem ved f om contact wi t d walls of the tire '1, Inaddition as pressure is applied to the tir '1 each of the springs M isbent inwardly and with the resu t that e c pressure plat it exerts thesame pressure on the tire T as the balance or the plates when the tire Tis removed uniformly Irorn the rim on which it is mounted. Forconvenience the assembly of my invention 1 the pring it to the inn r sde f the pr ssure arm so by a cap screw it that engages internallytapped openings formed in both members. 13y lo sen ng th cap s rew toand extracti th pin t2 the pressure finger assembly F may be removedfrom the pressure arm 36) forrepairs or replacement should the occasionso require.

vTo permit the tire T to be moved rearwardly toward the pressure fingersF for removal from the rim R, a rod d6 of circular cross section isslidably mounted in a horizontal position within the bore of the spiderhub l8. Rigidly affixed to the rearwardly disposed extremity of the rod46, and situated on the side of the spider S opposite the pressure arms30, is a circular piston head 41 of conventional design that is slidablyenclosed in the hydraulic cylinder 0'. The hydraulic cylinder C includesa pair of piston heads 48 and 4:9, with a cylindrical shell 50 formed ofhigh tensile steel, supported therebetween. A number of stud bolts 5!engage openings provided in both of the cylinder heads 48 and t9, andserve to hold the hydraulic cylinder C together as a unit. For holdingthe hydraulic cylinder C in the desired horizontal position, thecylinder head 43 is welded or otherwise secured in a conventional mannerto the rearward side of the diagonal members ll of the spider S as bestseen in Figure 3. In order that the hydraulic cylinder C may be filledwith hydraulic fluid from time to time to replace that which may be lostafter long usage in my device, an upwardly extending L-shaped conduit 52is situated near the top of the cylinder head til, and is supplied witha removable filling plug Hydraulic fluid under pressure for actuatingthe piston t7! is supplied by a hydraulic pump 5 3 that is situated onthe base 53 and held in position thereon by a number of machine bolts 55that engage openings provided in both the base and pump. An electricmotor 52, adapted for use with the ordinary 11o volt electric powersupply normally found in the type of garage or building in which a tiredemounting mechanism such as mine would be installed, is similarlybolted to the base iii and connected to the motor 5'; by a coupling 5'5.Extending upwardly from the hydraulic pump 5 5 to the hydraulic cylinderC are a pair of conduits 5d and 59, with the upper end of conduit 58being affixed to a suitable fluid connection 55 disposed on the cylincer head at, and the conduit 59 being likewise connected to a similarfitting 6| situated on the cylinder head to. Either of the conduits 53or 59 may act as discharge or suction for the hydraulic pump M,depending upon it direction of rotation.

An electrical reversing switch 62 of conventional design is situated ata convenient, location on the spider S, and electrically connected tothe motor 56 by a pair of insulated conductors 63. A pair of insulatedconductors so extends from the switch 52 to the volt electric powersupply. The motor 56 may now beoperated in either direction with theresult that the pump 5% can discharge hydraulic fluid into either of theconduits 58 or 59. Upon. hydraulic fluid being discharged through one ofthe conduits so or 59 by the pump 54, an equal quantity of fluid iwithdrawn from the hydraulic cylinder 0 through the opposite conduitwhich is then acting as the pump suction. Thus, by controlling thedirection of rotation of the pump at with the electrical reversingswitch 62, the piston head 4'5 and the rod 36 attached thereto may bemoved. either rearwardly or forwardly at the will of the operator. Itwill be apparent from exnmlnom tion of Figure 3 that a cushion ofhydraulic fluid exists at all times on each side of the cylindercontained piston ill and prevents any horizontal movement of same,except when the pump M is operating Situated at the forwardly disposedend of the rod 46 is a portion at of reduced diameter that forms anannular shoulder to with the rearward portion 46 of the rod. Slldablymounted on the rod portion to is an annular collar 6i, with a truncated,hollow, centering cone 33 extending rearwardly from its forwardlydisposed edge with an increasing larger diameter, as best seen in Figure3. In the manufacture of my device I have found it desirable to have thecentering cone '68 and the annular ring 61 cast from steel as anintegral unit. It will be noted that the distance which the centeringcone 98 may move rearwardly on the shaft portion 65 is limited by theannular shoulder 96 contacting the rearward face of the collar 61.

' As the normal industrial wheel W is formed with a solid metallic web69 that extends inwardly from the rim R to a centrally disposed opening69a, which is provided in the web in order that the shaft of a vehiclemay pass therethrough, this same opening 69a may be employed forcentering the wheel W on my invention by inserting the truncated portionof the centering cone 68 therein. The wheel W is then moved rearwardlytoward the spider S until the increasing diameter of the centering cone6%) contacts the outer circumference of the opening 69a and preventsfurther rearward movement. The tire T on the wheel W is now perfectlyaligned with relation both to the rod 45 and the pressure fingers Fprior to having the tire T removed as may best be seen in Figure 3.

As an alternate form of the above described centering cone 68, and onethat functions equally well, a device such as shown in Figure may besubstituted. An annular collar Hi, adapted for being slidably mounted onthe shaft portion E5, has four outwardly extending plates 75 affixedthereto at an angle of substantially 90 degrees to one another. Each ofthe plates l! is roughly triangular in form, and is provided along itsoutwardly disposed hypotenuse with a series of steps 12, as may best beseen in Figure 5. Each of the steps 12 is in vertical alignment withsimilar steps provided on the other plates ii, and thus forms ahorizontal support for the wheel W when its centrally disposed opening69a is placed thereon. It will be apparent that as the steps 12 aregraduated upwardly and rearwardly to correspond with the diameter of theopenings 69a provided on wheels W of variou sizes, that this deviceoperates in much the same manner as the centering cone 98. However thealternate form of the centering cone does have the advantage that whenthe wheel W is placed on the steps 12, it remains in place, and has notendency to slide forwardly as is the situation when the wheel W isplaced on the centering cone 58.

For retaining the wheel W in place on either the centering cone 68 orthe steps '42, the for wardly disposed section of the shaft portion 65is provided with threads 13 that are adapted to engage an internallythreaded collar l t. Extending rearwardly from the collar M with anincreasing larger diameter is a hollow pressure cone (5 that terminatesat its base periphery in a substantially vertical flange it. Thus, uponrotating the collar 14 the pressure cone i5 is moved rearwardly and thewheel W whether mounted on the centering cone 58 or the steps 12 isfirmly held in position thereon by the vertical flange I6 engaging theforwardly disposed surface of the wheel flange 69 as shown in Figure 3.It will be noted that the pressure cone 68 is substantially enveloped bythe centering cone 15 when the latter is holding a wheel W in placethereon.

To facilitate lifting a pneumatic tire carrying wheel W into place onthe centering cone $58 with a minimum of effort, a vertically disposedair cylinder H is mounted in a convenient location on the base [3 andmay be welded, bolted, or otherwise secured thereto. Telescopicallymounted in the cylinder TI is an inverted air cylinder 18 of somewhatgreater height thanthe cylinder 11. Rigidly supported from the top ofthe air cylinder 18 is a substantially horizontal boom 19 that ispreferably formed from an inverted T-beam having a vertical web and ahorizontal flange 8!. The boom l9 extends forwardly to a positionsomewhat beyond the wheel W when it is mounted on the pressure cone 68-or the steps 12 as may best be seen in Figures 1 and 3.

A pair of anti-friction rollers 82, each rotatable along the boom flange8| but situated on opposite sides of the web 80, support a downwardlyextending, inverted, U-shaped traveler 84 from horizontal outwardlyextending shafts 83, that may be affixed to the traveler in anyconvenient manner. A downturned angle iron member 85 aflixed to theforwardly disposed end of the boom 19 by machine bolts 86 prevents thetraveler 84 from being inadvertently displaced therefrom. Extendingdownwardly from the traveler 84 is a lift cable 81 which serves tosupport a conventional grab hook 88. Suspended from the grab hook 88 isa tong bridle 89 that engages a pair of lift tongs 90, as may best beseen in Figures 1, 2 and 3.

In order that the tongs 90 may be utilized for lifting a wheel W fromthe floor to a position on the centering cone 68, the boom 19 is movedupwardly by applying air under pressure to the space enclosed by thecylinders 11 and 73. For controlling the flow of air to the cylinders lland 78, a conventional three position air valve 9| with an air inletport 92, a combination air inlet and outlet port 93, and an outlet port94- which is vented to the atmosphere, is located at an easilyaccessible position on the spider S.

A conduit that may be either flexible or rigid, extends from the airvalve port 92 to a source of air under pressure that will normally befound available in a garage or building such as my invention would besituated in. Extending upwardly from the air valve port 93 to a suitableair fitting 96 situated on the upper portion of the air cylinder 18 is aflexible hose 9'1! with considerable slack provided therein. It will beapparent from Figure 1 that the amount of slack required in the hose 9'!will be that required to allow the air cylinder 18 to move upwardly toits maximum operating height.

To move the boom 19 upwardly the air valve 9| is rotated from its firstor normally closed position to its second position wherein the ports 92and 93 are in communication with one another. The air is then forcedthrough the hose 9'! into the space enclosed by the air cylinders TI and18, and as the air pressure is built up therein the cylinder 18 and theboom 19 are moved upwardly. When the desired height has been attained bythe boom 19, the air valve 9] is returned to its first position, andwith the result that the boom will remain in a stationary position dueto the inability of the air to escape from the cylinders 11 and 18. Inlowering the boom 19 the air valve 9| is rotated to the third positionin which the inlet port 92 remains closed but communication isestablished between the ports 93 and 94. As the cylinder contained airescapes to the atmosphere through the port 94 the weight of the boom 19forces the air cylinder 18 downwardly until its lower edge is resting onthe base of the air cylinder 11. In order that the boom 19 may berestrained from rising above a certain pre-determined maximum height, aswell as to prevent the cylinder 18 from being accidentally displacedfrom the cylinder 11, a

. (9 .ehain 9.8 is c nnected to b th th heom 19 a the air hy-linder 11-1best s en i figure sl- Althons the c a n .98 has been to re shi satisfat ry restrainin th thw rt mer rheht of th poem 1.9, t w l be a ps that amemb r may be connect d b twe n the hee and the a valve 9. so wh n the hart ha reached a ce ta n ma imum height the ei sh h t h ev ind rs T and18 w ll he aut matiaal r For r nf rc n th ide rarae asehis an suddenshock Wh eh ma h incurred t operat on f my ve tion. I ne r de reihereihs bars 99 w t e rea wa d v f om he oute h t l d a membe H t9sheet-P192 a the pres 1. n Seen in Figure In the operation of myinvention the wheel W is laid on th dee and the h eiimetie ti T mountedthereon is def lated to substantially at-, mospheric pressure. Ademountable steel ring (not shown) which due to its resiliency is -.he1d.in

.a groove .Itl situated on .the ,outer edgeof ;the

rim R is then removed. The time T isinow .in a

position to be slidably removed fromlthe R,

traveler .34 runout .to a, position above the fwheel W, and the lifttongs 9!] affixed to thestire T mounted thereon. Air valve .51! is nowplaced in a position to permit air to flow through the hose :91 into theair cylinders "11 and l8,. arid-.-with the result-that-the cylinderJ8,1the boom 1 9, and

the wheel W are moved upwardly.

Upon the shaft 46 and the center of the opening 6% coming intosubstantially horizontal alignment, the valve 9| is rotated to theclosed position to prevent further upward movement of the boom '19. Theshaft portion 65 is inserted into the wheel opening 69a, and the wheel Wmoved rearwardly until further movement is made impossible by thecentering cone 68 fully occupying the opening 690. With the wheel W heldin this position from the tongs 90, the collar 74 is caused to engagethe shaft threads 13, and then rotated to move the pressure cone 15rearwardly. Upon the flange 16 of the pressure cone l5 contacting theforwardly disposed face of the wheel web 69, the wheel W is firmly heldin position on the centering cone 68, and the boom 19 is no longerrequired. The boom 19 may now be swung into a position in which the lifttongs so will not interfere with the work of removing the tire T. Theair valve 9| is rotated to the third position that allows the cylindercontained air to escape from the valve port 94 to the atmosphere, andpermits the air cylinder 18 and the boom 19 to move downwardly intotheir initial position. For the most eificient operation of my inventionI have found it desirable to be concurrently deflating a number of tiresT, and placing one of them on the lift tongs 90, during the time thatanother tire T is being removed from its wheel W on my invention.

With the wheel W in position on the centering cone 615 the crank 24 isrotated, and the internally threaded member 26 moves inwardly oroutwardly dependent upon the direction of the crank rotation. Due to thelink 29 movably connecting the member 26 and the circular cam plate 20,the lateral movement of the member 26 assess:

sense by the retailer; o the e ah 2 results i rot tion f the e As t an;lat 29 is rotated a co c rren ed al mov men o t pressur arms .3 take p ae due to t disn aeer ht f the onne t n lin s it as ma b st b seen Fi ure12- Each of t e nks a jus a le hath as to ts thr w an the spe d e itsinva id .or n ward rad a m vement which is dehe d n on wheth r it iivoted t the .eam :2 evenin it? .or at Whi e norm l he 4. 5 w ll e votedto the e s late it in th openings 39, if a tire of unusual size isencount hee the links may he mo ed out to en age the .Q e as a w ich w cease the .o twar 1 1' movemen cf the p essure a ms 9- v ro t n the crant th pr ssure a ms t ;e e. mey i.tha.n sition in which the e e sea epressu e in ers F wi lust c ea th oute ,neh r-hervh ,a reerwa ly dsposed flan .l 12 vo tr m R as hes se in Fi ur h .e1 e trical switch 62is now placed in apositionwhich will cause the motor driven pump 54tojrntate in a direction that will force hydraulic fluid through theconduit :53 into the right hand side of the chv-drahl e qylinderc as.rnavh-est be .se nin Ei ,ures l 3. When hydraulic fluid .is forced{into the vcylinderC, the piston head All ,andthe re A6 atta he there oa move rearwardly. t. ithe-whee W bein idly afhxedto thel o rfliibetween th .eeh e ns cone t8 and the pressur one-' is li ewis mo d awarolv. with the j erlas of th ti -T a i the tapered li e slate the whee1W a dth tire .T m verearwar-dh es ur 'f hsers heinspiv al yrhouhted lie Qt pr sur a o ated ward y ,rg h tth ed e Ate Of the pr ssu e plat be nforced between the flange Hi2 and the bead of the tire. The downwardrotation of the pressure fingers F will continue until the edge 130: ofeach of the pressure plates lit contacts the exterior surface of the rimR, whereupon the tire T begins to be slidably demounted. Due to each ofthe pressure fingers F being provided with a leaf spring A l that tendsto force the pressure plate 53 forwardly and upwardly each pressureplate exerts the same force upon the tire T as the balance of thepressure plates when the tire T is removed uniformly from the rim onwhich it is mounted. However, upon a portion of the tire T adhering tothe rim on which it is mounted, the lower downwardly extending portionof the pressure member 33 which is in contact with the adhering portionof the tire is bent rearwardly to place a gradually increasing pressureon the tire. After the lower portion of the member 43 being bentrearwardly a certain distance, sufficient pressure is exerted on thetire due to the rearward movement thereof to break the adhering tireportion loose. Upon the adhering tire portion being broken loose themember 43 due to the resiliency thereof pushes the tire forwardly intosubstantially the same vertical plane as the balance of the members andtire. As the springs 44 tend to oppose the fingers F pivoting inwardly,the fingers after contacting the tire are kept in contact therewithuntil the tire is displaced from the rim. The wheel W is movedrearwardly on my invention until the tire T is slidably removed from therim R, and at which point the pressure fingers E are forced upwardlyinto substantial alignment with the pressure arms 30 by the resiliencyof the leaf springs 4G. The pressure fingers F are thus out of the pathof the flange I02, when the wheel W is moved forwardly to the positionit occupied prior to having the tire T removed therefrom. The forwardmovement of the wheel W is achieved by reversing the electrical switch52 and changing the direction of rotation of the motor 55. As the pump54 is revolved in the opposite direction hydraulic fluid is forcedthrough the conduit 59,

' and withdrawn from the cylinder C through the conduit 58, thus forcingthe piston head 41 forwardly and returning the centering cone 68 andpressure cone 15 to their position for removing the wheel W.

While the particular apparatus herein shown and described is fullycapable of attaining the objects and providing the advantages hereinbefore stated, it is to be understood that it is merely illustrative ofthe presently preferred form of my invention, and that I do not mean tolimit myself to the details of construction or design herein shown,other than defined in the appended claim.

I claim:

A tire demounting apparatus which includes: a supporting frame having aplurality of radial members extending outwardly from a central axis;means for supporting a flanged rim with a tire thereon and moving thesame along said axis toward said frame; a pressure arm slidably mountedon each of said radial members for movement therealong, said armsextending longitudinally of said axis and spaced therefrom; means foradjusting the radial position of said pressure arms; a relatively shortpressure shoe pivotally mounted on the outer end portion of each of saidpressure arms, each of said shoes being formed of spaced parallel plateshaving rearwardly and outwardly extending portions at one oftheir endswith a pivot pin extending therebetween and engaging said pressure arm,each of said shoes having a relatively short fiat pressure plate thereonjoining the free ends of said parallel plates and extending angularlyinwardly from the outward edges of said parallel plates whereby toengage a tire being advanced toward said frame and to be forced inwardlybetween the bead of said tire and the flange of said rim, said pressureplates being of suflicient rigidity and strength to force said tire fromsaid rim as the rim continues to move toward said frame; and springmeans engaging the inward edges of the parallel plates of each of saidpressure shoes and urging them outwardly to a position longitudinal ofsaid frame axis.

ERNEST DOUGLASS.

References Cited in the file of this patent UNITED STATES PATENTS Number'Name Date 1,399,351 Lee Dec. 6, 1921 1,724,813 Weaver et a1. Aug. 13,1929 1,742,590 Freivogel Jan. 7, 1930 1,959,655 Brouhard May 22, 19342,075,421 Bennett Mar. 30, 1937 2,201,982 Bazarek May 28, 1940 2,270,657Kraft Jan. 20, 1942 2,373,975 Plumeau et a1 Apr. 17, 1945 2,508,520Johnson May 23, 1959 2,536,139 Ritter Jan. 2, 1951 2,545,157 McCraryMar. 13, 1951 FOREIGN PATENTS Number Country Date 395,406 Germany May19, 1924

